I'm not seeing how you can "saber" a bottle of champagne without breaking off a part of the glass. I saw this demonstrated at a winery in the Champagne region of France some years back, and cleanly breaking off the top ring of the bottle is what it's all about. Maybe if you carefully loosened the cork first, to the point where it was about to pop on its own, then you could just knock it the rest of the way with a saber. But then, the French would tell you that you are not really "sabering" the bottle if you do it that way. You know those French, they like things to be done the "right" way. :-)

In any case, I would hope we can all agree that if you are deliberately knocking broken glass into the water, you are being very irresponsible.